Patterns of colonising and pneumonic organisms in intubated ICU patients - a prospective analysis

Abstract

The incidence and nature of upper respiratory tract colonisation and pneumonia were prospectively studied in 102 sequential patients admitted to a general intensive care unit (ICU) requiring tracheal intubation for longer than 48 hours. Endotracheal sampling for quantitative cultures was performed upon all patients twice weekly. Twenty-three patients (22%) developed pneumonia of whom seven (30%) died. Colonisation occurred in 28 patients, showing exclusively a Gram-negative pattern. Colonisation proved a poor predictor of pneumonia with a sensitivity of 35%, specificity of 75% and a positive predictive value of 29%. There was no significant difference in the incidence of pneumonia between patients who were colonised and those who were not colonised (p>0.4). The pattern of causative organisms for pneumonia were Gram-negative bacilli (60%), Gram-positive organisms (30%), polymicrobial (26%) and culture negative (8%). Of the eight patients who were colonised and developed pneumonia, six (75%) were infecte...